GARDENERS’ QUERIES

Press, Volume CXII, Issue 33094, 8 December 1972, Page 15

GARDENERS’ QUERIES

Our lettuces, which have been quickly grown and well watered, nearly all have patches of slimy rotten leaves around the heart which cannot be seen until the outer green leaves have been removed. They are picked as soon as the hearts are firm. I have not encountered this condition until moving to this property two years ago so wondered if some-

thing would be lacking in the soil? — Mrs H. (Banks Peninsula). There are two or three diseases which can cause similar symptoms on lettuces and only examination or accurate details of their condition can determine which it is. However, bacterial soft rot would seem to fit most closely to the condition which you describe. After infection a lettuce plant

rapidly decays, producing an unpleasant smell. The infection usually gains entry through a primary cause such as after-infection from another disease or damage caused by insects, etc. Excessive overhead watering, especially when weather conditions are warm and humid, are ideal for development and spread of this disease, which can become soil-borne.

I enclose some poppy heads. Each year they go like this. The stem bends over and goes black and the flowers do not open. Can you please tell me the cause and what I can do? — “Kay” (Westland). It would appear that the Clants are being attacked by otrytis disease. Regular spraying with thiram should control this trouble.

Enclosed is a sample of a plant which has increased considerably in my garden in the last two years. Could you please name it and advise any treatment to eradicate it? — P.B. (Christchurch). Your weed problem is pearlwort which is a perennial that can be a nuisance

on lawns. One of the proprietary weed-killers will give effective control. I would be grateful if you would name the enclosed specimen and also the country from which it comes. — R.W. (Diamond Harbour). The specimen is that of hakea which is indigenous to Australia. A flowering branch would aid in recognition of species. Could you please give some advice on the growing of Bird of Paradise lilies? I have two plants in my garden and although they are quite good they have not developed a great deal in six years. Also could you tell me why the flowers should produce double heads as in the accompanying sketch? — E.D. (Christchurch). There seems nothing odd about the flowering of your Strelitzia which is behaving in the normal way. These plants are not really suitable for planting in the garden on the flats round Christchurch if they are to really thrive. They require plenty of warmth, good soil and satisfactory drainage. Moisture is most desirable over the drier summer months. The plants are likely to suffer from frost damage.